This application relates to an improved blood collection apparatus and method in which the separation of Factor VIII rich cryoprecipitate from the remainder of the blood plasma is facilitated in an improved manner and in which the yield of Factor VIII rich cryoprecipitate is improved.
Many thousands of units of blood are collected each year in multiple bag blood collection systems comprising several blood compatible, sealed bags connected together with blood compatible tubing.
In a typical operation, a donor needle is inserted into the vein of a patient. This needle is connected by suitable tubing, such as vinyl tubing, to a first blood bag containing a small amount of conventional blood cell preservative, such as ACD or CPD. The blood is allowed to fill the first blood bag of the system, the donor needle is withdrawn from the patient, and the tubing connecting the needle to the bag is sealed. Following this, the blood collection system is centrifuged to cause the blood cells to settle and separate from the plasma. The plasma is then expressed through another tubing into a second blood bag, while the cells remain in the first blood bag.
Optionally, platelets may be harvested at this stage by a second centrifugation.
The plasma in the second blood bag is then frozen, either by refrigeration or by immersion in a mixture of dry ice and ethanol or a similar solvent.
After this, the frozen plasma is conventionally allowed to thaw slowly and then is centrifuged once again to settle solid material in the cold, thawed plasma. This solid material is known as Factor VIII rich cryoprecipitate.
After the conventional centrifuging, the plasma, which is now cryoprecipitate-poor, is expressed through tubing into a third blood bag for use, leaving behind the Factor VIII rich cryoprecipitate. This Factor VIII rich cryoprecipitate is the source of an important therapeutic agent for arresting the symptoms of a common type of hemophilia.
In accordance with this invention, an apparatus and a method of using the same is provided which permits the collection of increased yields of Factor VIII rich cryoprecipitate without the use of a second centrifuging step and which provides substantial savings in time and effort when compared with the present technique for obtaining Factor VIII rich cryoprecipitate.